Method of preparing derivatives of polyarylene vinylene and method of preparing an electronic device including same

ABSTRACT

A technique is described for the preparation of polymers according to a new process, in which the starting compound of formula (I) is polymerized in the presence of a base, in an organic solvent. The precursor polymer such obtained comprises structural units of the formula (II). In a next step, the precursor polymer (II) is subjected to a conversion reaction by thermal treatment. The arylene or heteroarylene polymer comprises structural units of the formula III. In this new process the dithiocarbamate group acts as a leaving group and permits the formation of a precursor polymer of structural formula (II), which has an average molecular weight from 5.000 to 500.000 Dalton and is soluble in common organic solvents. The precursor polymer with structural units of formula (II) is thermally converted to the conjugated polymer with structural formula (III).

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for the preparation of aryleneand heteroarylene vinylene polymers by thermal conversion of a novelprecursor polymer and to devices including same. Furthermore, thisinvention relates to a method for the direct preparation of novelpolyiniferters.

BACKGROUND OF THE INVENTION

Conjugated polymers are of great interest for the development of opticaland electronic applications. The most investigated conjugated polymersare poly(thiophene) (PT) and poly(p-phenylene vinylene) (PPV). Alsopoly(2,5-thienylene vinylene) (PTV) has attracted great attentionbecause of its high electrical conductivity upon doping and its possibleapplication as a semiconductor in all-polymer field effect transistors.Additionally, PTV is a low band gap semiconductor polymer, which makesit a very interesting material for organic photovoltaic devices.

Several method have been developed to synthesize PVT. In the early days,PTV was synthesized via the Wessling polymerization method, which isdescribed in U.S. Pat. No. 3,401,152 by R. A. Wessling and R. G.Zimmerman and in J. Polym. Sci.: Polym. Symp. 1985, 72, 55 by R. A.Wessling. The polymerization reaction according to the Wessling methodis difficult, because the products tend to form a gel. Moreover, strongacids, which could be toxic, are required during the conversionreaction.

In 1987, Murase et al. and Yamada et al. reported the synthesis of PTVvia a precursor polymer with methoxy leaving groups (I. Murase, T.Ohnishi, T. Noguchi, M. Hirooka, Polym. Commun. 1987, 28, 229; S.Yamada, S. Tokito, T. Tsutsui, S. Saito, J. Chem. Soc., Chem. Commun.1987, 1448). This reaction is an acid catalysed conversion reaction,which is incompatible with device fabrication.

In 1990, Elsenbaumer et al. reported the synthesis and characterisationof PTV and some alkyl-substituted PTV's (R. L. Elsenbaumer, Mol. Cryst.Liq. Cryst 1990, 186, 211). These methods are far from ideal especiallyfor the PTV derivatives due to the relative high reactivity of themonomer and precursor polymer which complicates both monomer and polymersynthesis. The high reactivity is originated from the high electrondensity of the thiophene ring, which induces a very high instability ofthe starting monomer when this monomer is reached but generally with lowreproducibility and very low yields due to many side-reactions.

This is also the reason why problems occur by using the more recentprecursor methods like the sulfinyl route, developed by Vanderzande etal. in 1997 (A. J. J. M. Van Breemen, A. C. J. Issaris, M. M. de Kok, M.J. A. N. Van Der Borght, P. J. Adriaensens, J. M. J. V. Gelan, D. J. M.Vanderzande, Macromolecules 1999, 32, (18), 5728), the bis-xanthateroute developed by Son in 1995 and Burn et al. in 2001 and described in(US patent 1997/5,621,069, European patent EP 0 707 022 A2; S-C. Lo,L.-O. Palsson, M. Kilitziraki, P. L. Burn, I. D. W. Samuel, J. Mater.Chem. 2001, 11, 2228) and the bis-sulfide route developed by Herwig etal in 2003 (US patent 2003/10027963 A1).

To use PTV, other poly(arylene vinylene)s and poly(heteroarylenevinylene) derivatives in plastic electronics, an easy accessibleprecursor polymer that can be manufactured on a large scale is aprerequisite.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method for thesynthesis of low band gap conjugated polymers like arylene ofheteroarylene vinylene, in good yields, with high molecular weight, goodquality (low defect level) and in large scale. It is a further aim ofthis invention to describe the use of conjugated polymers for organicsolar cells, organic transistors and all other kind of electronicdevices.

It is a further aim to describe a novel precursor polymer, to be used aintermediate compound in the synthesis of arylene of heteroarylenevinylene polymers.

Furthermore, it is an object of the present invention to describe thesynthesis of novel polyiniferters by direct introduction of iniferterfunctionalities in the polyiniferter polymer (initiator-transferagent-terminator). Polyiniferters can be used in iniferters controlledfree-radical polymerisation technique for the synthesis of blockcopolymers.

In a first aspect of this invention, a method for the preparation of aprecursor polymer is disclosed. The precursor polymer has the generalformula

wherein Ar is an aromatic divalent group or a heteroaromatic divalentgroup, wherein R₁ and R₂ are independently from each other an organicgroup selected from the group consisting of a C₁-C₂₀-alkyl group, acyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, anarylalkyl group and a heterocyclic group, and wherein R₃ and R₄ areindependently from each other hydrogen or an organic group selected fromthe group consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkylgroup, an aryl group, an alkylaryl group, an arylalkyl group and aheterocyclic group. The method comprises the steps of:

-   -   providing a monomer having the general formula:        wherein Ar is an aromatic divalent group or a heteroaromatic        divalent group, wherein R₁ and R₂ are independently from each        other an organic group selected from the group consisting of a        C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an aryl group,        an alkylaryl group, an arylalkyl group and a heterocyclic group,        and    -   reacting said monomer with a basic compound in the presence of        an organic solvent to obtain said precursor polymer.        The basic compound may be selected from the group consisting of        a metal oxide, a metal alkoxide, a metal amide, organometal        compounds, grignard reagents and ammonium hydroxide. The amount        of basic compound may be between 1 and 2 equivalents with        respect to the monomer.        The concentration of the monomer used in the method of the        present invention may be between 0.1 and 0.3 M.

In an embodiment of the first aspect of the invention, the Ar group maybe an aromatic divalent group with 4 to 20 carbon atoms which may besubstituted with one or more substituents independently selected fromthe group consisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy orC₁-C₂₀-alkylsulfate. These groups may comprise up to 4 heteroatomschosen from the group comprising oxygen, sulphur, and nitrogen in thearomatic divalent group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar is1,4-phenylene or 2,5-thienylene and most preferably Ar is2,5-thienylene.

In a preferred embodiment, R₁ and R₂ may be a C₁-C₂₀-alkyl group. Inanother embodiment, R₁ and R₂ may be selected from the group consistingof methyl, ethyl and isopropyl.

In a further embodiment of the first aspect of this invention, reactingthe monomer with a basic compound may be performed at a temperaturebetween −78° C. and 200° C., preferably between 40° C. and 120° C., andmost preferably between −20° C. and 30° C. The temperature may beselected such that the average molecular weight is as high as possibleand that the polydispersity is as low as possible.

The method as described in the first aspect of this invention mayrequire symmetrical starting monomers. Symmetrical starting moleculeshave the advantage that they are easier to synthesise than asymmetricstarting monomers. Furthermore, symmetrical starting monomers withdithiocarbamate groups are stable in time. The polymerisation of thesymmetrical monomer in a solvent and in the presence of a base may leadto a precursor polymer soluble in common organic solvents. Thosesolvents may be polar, apolar and mixtures thereof. The solvent may forexample be an aprotic solvent. The dithiocarbamate groups act as aleaving group and as a polarizer during the polymerisation.

Furthermore, the present invention provides a precursor polymer with theformula:

wherein Ar is an aromatic or heteroaromatic divalent group, wherein R₁and R₂ are chosen from the group consisting of a C₁-C₂₀-alkyl group, acyclic C₄-C₂₀-alkyl group, a phenyl group and a benzyl group. TheC₁-C₂₀-alkyl group, cyclic C₄-C₂₀-alkyl group, phenyl group and benzylgroup may comprise heteroatoms and substituents. In a preferredembodiment, R₁ and R₂ may independently be selected from methyl, ethylor propyl. R₃ and R₄ are chosen from the group comprising a hydrogenatom and a C₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, a phenylgroup and a benzyl group, which groups may comprise heteroatoms andsubstituents. In a preferred embodiment, R₃ and R₄ may be hydrogen. Allpossible combinations of Ar, R₁, R₂, R₃ en R₄ may be included in thisinvention.

In a preferred embodiment, Ar may comprise 4 to 20 carbon atoms. Inanother embodiment, the Ar groups may be substituted with a substituentchosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

The precursor polymers, according to present invention, may show highmolecular weight, between 5000 and 500000, more particularly between7.000 and 250.000, especially between 7.500 and 100.000 Dalton.Furthermore, the polydispersity of the precursor polymers, according tothe present invention, may be between 1.5 and 5.5, preferably below 2.The precursor polymer may be obtained in good overall yields in areproducible way. Large-scale production may be a possibility.

In a second aspect of this invention, a method for the preparation ofconjugated arylene and heteroarylene vinylene polymers is disclosed.Said conjugated arylene heteroarylene vinylene polymers have the generalformula

wherein Ar is equal to the Ar group in the first aspect of thisinvention.

The method comprises the steps of:

-   -   providing at least one precursor polymer having the general        formula:        wherein Ar is an aromatic divalent group or an heteroaromatic        divalent group, wherein R₁, R₂, are independently from each        other an organic group selected from the group consisting of a        C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an aryl group,        an alkylaryl group, an arylalkyl group and a heterocyclic group,        and wherein R₃ and R₄ are independently from each other hydrogen        or an organic group selected from the group consisting of a        C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an aryl group,        an alkylaryl group, an arylalkyl group and a heterocyclic group,        and    -   subjecting the precursor polymer to a thermal conversion step at        a temperature between 30° C. and 300° C.

The precursor polymer may be synthesized according to the methoddescribed in the first aspect of this invention. In one embodiment ofthe second aspect of this invention, the duration of the subjecting stepmay be lower than 24 hours, lower than 8 hours and preferably lower than2 hours.

In an embodiment of the first aspect of the invention, the Ar group maybe an aromatic divalent group with 4 to 20 carbon atoms which may besubstituted with one or more substituents independently selected fromthe group consisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl group or a benzyl group. These groups maycomprise up to 4 heteroatoms chosen from the group comprising oxygen,sulphur, and nitrogen in the aromatic divalent group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar is1,4-phenylene or 2,5-thienylene and most preferably Ar is2,5-thienylene.

The conjugated arylene or heteroarylene vinylene polymers may beobtained by thermal conversion of the precursor polymer in which theremaining dithiocarbamate group acts as a leaving group (or evaporatinggroup). The conjugated polymer may show a low structural defect level.

In a preferred embodiment, R₁ and R₂ may be a C₁-C₂₀-alkyl group. Inanother embodiment, R₁ and R₂ may be selected from the group consistingof methyl, ethyl or propyl.

In a preferred embodiment, R₃ and R₄ may be hydrogen.

In a preferred embodiment, said conjugated arylene vinylene polymer ispoly (2,5 thienylene vinylene).

In a further embodiment of the second aspect of this invention theprecursor polymer may be in the form of a thin film precursor polymerlayer and the thermal conversion step may be performed under inertatmosphere.

In a further embodiment of the second aspect of this invention, theprecursor polymer may be dissolved in a solvent, followed by a degassingstep.

In a further embodiment of the second aspect of this invention, thethermal conversion step may be performed at a temperature between 30° C.and 300° C., preferably between 80° C. and 300° C., and most preferablybetween 115° C. and 250° C.

In a further embodiment of the second aspect of this invention the yieldof the method may be between 50% and 90%.

Compared to the Wessling route, the method of the present invention hasthe advantage of leading to polymerisation without gel formation andrequiring no toxic gas (like strong acids) during the conversionreaction.

Compared to the Gilch route, this invention has the advantages ofleading to polymers that can also be insoluble in their conjugated form.The Gilch route is a one-pot polymerisation, which only allows thesynthesis of soluble conjugated polymers; it is not a precursor route.

Compared to the sulfinyl route, this invention has the advantages ofleading to stable monomers.

Precursor polymers synthesised from a monomer having a symmetricalstructure may be much easier to synthesise and to obtain in good yield.No complicated purification step by chromatography column of the monomeris requested.

Precursor polymers with leaving groups (e.g. dithiocarbamate) arecompatible with a device application. The lifetime of the device is notinfluenced by remaining traces of leaving groups in the active layerafter the conversion reaction.

Compared to the bis-sulfide route, the method of the present inventionhas the advantage of leading to polymers having less structural defectsin the backbone. In the bis-sulfide route, over-oxidation can occureasily as the oxidation of the sulfide groups is carried out afterpolymerisation and not on the starting monomer. Structural defects havea negative effect on the charge mobility of conjugated polymers

Compared to the bis-anthate route, this invention has the advantages ofleading to:

-   -   monomers and precursor polymers stable in time in inert        atmosphere.    -   polymers with a much lower polydispersity around 2 to 3 (while        being between 20 and 30 for the xanthate-route).    -   reproducibility between batches.    -   polymers obtained through polymerisation reaction carried out at        a temperature ranging from −78° C. to room temperature.    -   the yield of the polymerisation reaction is higher than 50%.    -   polymers with low defect level.    -   polymers with increased λ_(max) (around 545 nm for PTV at high        temperature and 570 nm at RT, only 500-520 nm at high        temperature for the xanthate-route depending on batches).    -   large-scale synthesis is possible.

Furthermore, the present invention provides a conjugated arylene orheteroarylene vinylene polymer with the general formula

wherein Ar is an aromatic group or an heteroaromatic divalent group,wherein R₃ and R₄ are independently from each other hydrogen or anorganic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group,an arylalkyl group and a heterocyclic group, and wherein n is an integerfrom 5 to 2000. The polymer of the present invention show a peak at awavelength higher than 520 nm in the absorption spectrum.

In a preferred embodiment, Ar comprises 4 to 20 carbon atoms. In anotherembodiment, the Ar groups may be substituted with a substituent chosenfrom the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

All possible combination of Ar, R₁, R₂, R₃ and R₄ are included in thisinvention.

The polymer, prepared according to a method described in the previousembodiments has less defects with respect to the prior art.

In a preferred embodiment, the polymer may be characterized by a peak ata wavelength higher than 540 nm in the absorption spectrum.

In a preferred embodiment of the invention, the conjugated arylene orheteroarylene vinylene polymer may be poly(2,5 thienylene vinylene).

The average molecular weight of the polymer according to the inventionmay be between 5000 daltons and 500000 daltons, whereas thepolydispersity may be between 1.5 and 5.5. Furthermore, the polymeraccording to the present invention may be a linear polymer.

In a third aspect of this invention, an electronic device is provided.The electronic device comprises a the polymer layer according to thepresent invention and thus having the formula (III). Ar, R₃ and R₄ areequal to Ar, R₃ and R₄ as described in the first and the second aspectof this invention. The electronic device according to the third aspectof this invention has several advantages. The polymers were found tohave less defects. As a result, the polymer has better properties,resulting in a better electronic device.

In a first embodiment of the third aspect of the present invention, thedevice may be a light-emitting diode. The light-emitting diode maycomprise polymers having structural units of formula (III). Preferably,Ar may be 1,4-phenylene or 2,5-thienylene while R₃ and R₄ may behydrogen.

In a further embodiment, the device may be an integrated circuit ororganic transistor. The integrated circuit may comprise polymers havingstructural units of formula (III), wherein Ar preferably may be1,4-phenylene or 2,5-thienylene while R₃ and R₄ may be hydrogen. Suchintegrated circuits have the advantage of having a lower cost price.

The invention further provides a method of direct preparation ofpolyiniferters polymers to be used as photoiniferters in inifertercontrolled free-radical polymerisation techniques for the synthesis ofblock copolymers.

The invention further relates to a method of manufacturing a layer of apolymer with structural units having the formula (II) or (III).

The invention further relates to a method of manufacturing bilayerheterojunction organic solar cells using a polymer containing structuralunits of formula (II). The active layer made from the precursor polymermay become effectively active only after heat treatment.

Furthermore, the invention relates to a method of manufacturing organicbulk heterojunction solar cells using as an active layer a blend of ann-type material, such as a soluble C₆₀, and a p-type material, such as aprecursor polymer containing structural units of formula (II). Theactive layer made from the n-type/p-type materials may become an activelayer only after the conversion reaction of the thin film by heattreatment.

The invention further relates to a method of manufacturing organictransistors using a polymer containing structural units of formula (II).The active layer made from the precursor polymer may become effectivelyactive only after heat treatment.

In a fourth aspect of this invention, a method for manufacturing anelectronic device is disclosed. The electronic device comprises apolymer layer. In the method according to the present invention, a layercomprising the precursor polymer (II) is deposited. In a next step, thepolymer (III) layer is obtained by carrying out the conversion reactionby heat treatment of the precursor polymer layer according to the secondaspect of this invention.

These and other characteristics, features and advantages of the presentinvention will become apparent from the following detailed description.

DEFINITIONS

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₁₋₇ alkyl” or “aliphatic saturatedhydrocarbon radicals with 1 to 7 carbon atoms” means straight andbranched chain saturated acyclic hydrocarbon monovalent radicals havingfrom 1 to 7 carbon atoms such as, for example, methyl, ethyl, propyl,n-butyl, 1-methylethyl (isopropyl), 2-methylpropyl (isobutyl),1,1-dimethylethyl (ter-butyl), 2-methyl-butyl, n-pentyl, dimethylpropyl,n-hexyl, 2-methylpentyl, 3-methylpentyl, n-heptyl and the like; the term“C₁₋₄ alkyl” designate the corresponding radicals with only 1 to 4carbon atoms, and so on.

As used herein with respect to a substituting radical, and unlessotherwise stated, the term “C₁₋₇ alkylene” means the divalenthydrocarbon radical corresponding to the above defined C₁₋₇ alkyl, suchas methylene, bis(methylene), tris(methylene), tetramethylene,hexamethylene and the like.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₃₋₁₀ cycloalkyl” and “cycloaliphaticsaturated hydrocarbon radical with 3 to 10 carbon atoms” mean a mono- orpolycyclic saturated hydrocarbon monovalent radical having from 3 to 10carbon atoms, such as for instance cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl and the like, or a C₇₋₁₀ polycyclicsaturated hydrocarbon monovalent radical having from 7 to 10 carbonatoms such as, for instance, norbornyl, fenchyl, trimethyltricycloheptylor adamantyl.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “aryl” and “aromatic substituent” areinterchangeable and designate any mono- or polycyclic aromaticmonovalent hydrocarbon radical having from 6 up to 30 carbon atoms suchas but not limited to phenyl, naphthyl, anthracenyl, phenantracyl,fluoranthenyl, chrysenyl, pyrenyl, biphenylyl, terphenyl, picenyl,indenyl, biphenyl, indacenyl, benzocyclobutenyl, benzocyclooctenyl andthe like, including fused benzo-C₄₋₈ cycloalkyl radicals (the latterbeing as defined above) such as, for instance, indanyl,tetrahydronaphtyl, fluorenyl and the like, all of the said radicalsbeing optionally substituted with one or more substituents selected fromthe group consisting of halogen, amino, nitro, hydroxyl, sulfhydryl andnitro, such as for instance 4-fluorophenyl, 4-chlorophenyl,3,4-dichlorophenyl, 4-cyanophenyl.

As used herein with respect to a substituting radical (including thecombination of two substituting radicals), and unless otherwise stated,the term “heterocyclic” means a mono- or polycyclic, saturated ormono-unsaturated or polyunsaturated monovalent hydrocarbon radicalhaving from 2 up to 15 carbon atoms and including one or moreheteroatoms in one or more heterocyclic rings, each of said rings havingfrom 3 to 10 atoms (and optionally further including one or moreheteroatoms attached to one or more carbon atoms of said ring, forinstance in the form of a carbonyl or thiocarbonyl or selenocarbonylgroup, and/or to one or more heteroatoms of said ring, for instance inthe form of a sulfone, sulfoxide, N-oxide, phosphate, phosphonate orselenium oxide group), each of said heteroatoms being independentlyselected from the group consisting of nitrogen, oxygen, sulfur, seleniumand phosphorus, also including radicals wherein a heterocyclic ring isfused to one or more aromatic hydrocarbon rings for instance in the formof benzo-fused, dibenzo-fused and naphto-fused heterocyclic radicals;within this definition are included heterocyclic radicals such as, butnot limited to, diazepinyl, oxadiazinyl, thiadiazinyl, dithiazinyl,triazolonyl, diazepinonyl, triazepinyl, triazepinonyl, tetrazepinonyl,benzoquinolinyl, benzothiazinyl, benzothiazinonyl, benzoxathiinyl,benzodioxinyl, benzodithiinyl, benzoxazepinyl, benzo-thiazepinyl,benzodiazepinyl, benzodioxepinyl, benzodithiepinyl, benzoxazocinyl,benzothiazocinyl, benzodiazocinyl, benzoxathiocinyl, benzo-dioxocinyl,benzotrioxepinyl, benzoxathiazepinyl, benzoxadiazepinyl,benzothiadiazepinyl, benzotriazepinyl, benzoxathiepinyl,benzotriazinonyl, benzoxazolinonyl, azetidinonyl, azaspiroundecyl,dithiaspirodecyl, selenazinyl, selenazolyl, selenophenyl, hypoxanthinyl,azahypoxanthinyl, bipyrazinyl, bipyridinyl, oxazolidinyl,diselenopyrimidinyl, benzodioxocinyl, benzopyrenyl, benzopyranonyl,benzophenazinyl, benzoquinolizinyl, dibenzocarbazolyl, dibenzoacridinyl,dibenzophenazinyl, dibenzothiepinyl, dibenzooxepinyl, dibenzopyranonyl,dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzoisoquinolinyl,tetraazaadamantyl, thiatetraazaadamantyl, oxauracil, oxazinyl,dibenzothiophenyl, dibenzofuranyl, oxazolinyl, oxazolonyl, azaindolyl,azolonyl, thiazolinyl, thiazolonyl, thiazolidinyl, thiazanyl,pyrimidonyl, thiopyrimidonyl, thiamorpholinyl, azlactonyl,naphtindazolyl, naphtindolyl, naphtothiazolyl, naphtothioxolyl,naphtoxindolyl, naphtotriazolyl, naphtopyranyl, oxabicycloheptyl,azabenzimidazolyl, azacycloheptyl, azacyclooctyl, azacyclononyl,azabicyclononyl, tetrahydrofuryl, tetrahydropyranyl, tetrahydropyronyl,tetrahydroquinoleinyl, tetrahydrothienyl and dioxide thereof,dihydrothienyl dioxide, dioxindolyl, dioxinyl, dioxenyl, dioxazinyl,thioxanyl, thioxolyl, thiourazolyl, thiotriazolyl, thiopyranyl,thiopyronyl, coumarinyl, quinoleinyl oxyquinoleinyl, quinuclidinyl,xanthinyl, dihydropyranyl, benzodihydrofuryl, benzothiopyronyl,benzothiopyranyl, benzoxazinyl, benzoxazolyl, benzodioxolyl,benzodioxanyl, benzothiadiazolyl, benzotriazinyl, benzothiazolyl,benzoxazolyl, phenothioxinyl, phenothiazolyl, phenothienyl(benzothiofuranyl), phenopyronyl, phenoxazolyl, pyridinyl,dihydropyridinyl, tetrahydropyridinyl, piperidinyl, morpholinyl,thiomorpholinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl,tetrazinyl, triazolyl, benzotriazolyl, tetrazolyl, imidazolyl,pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, oxazolyl, oxadiazolyl,pyrrolyl, furyl, dihydrofuryl, furoyl, hydantoinyl, dioxolanyl,dioxolyl, dithianyl, dithienyl, dithiinyl, thienyl, indolyl, indazolyl,benzofuryl, quinolyl, quinazolinyl, quinoxalinyl, carbazolyl,phenoxazinyl, phenothiazinyl, xanthenyl, purinyl, benzothienyl,naphtothienyl, thianthrenyl, pyranyl, pyronyl, benzopyronyl,isobenzofuranyl, chromenyl, phenoxathiinyl, indolizinyl, quinolizinyl,isoquinolyl, phthalazinyl, naphthiridinyl, cinnolinyl, pteridinyl,carbolinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl,phenothiazinyl, imidazolinyl, imidazolidinyl, benzimidazolyl,pyrazolinyl, pyrazolidinyl, pyrrolinyl, pyrrolidinyl, piperazinyl,uridinyl, thymidinyl, cytidinyl, azirinyl, aziridinyl, diazirinyl,diaziridinyl, oxiranyl, oxaziridinyl, dioxiranyl, thiiranyl, azetyl,dihydroazetyl, azetidinyl, oxetyl, oxetanyl, thietyl, thietanyl,diazabicyclooctyl, diazetyl, diaziridinonyl, diaziridinethionyl,chromanyl, chromanonyl, thiochromanyl, thiochromanonyl, thiochromenyl,benzofuranyl, benzisothiazolyl, benzocarbazolyl, benzochromonyl,benzisoalloxazinyl, benzocoumarinyl, thiocoumarinyl, phenometoxazinyl,phenoparoxazinyl, phentriazinyl, thiodiazinyl, thiodiazolyl, indoxyl,thioindoxyl, benzodiazinyl (e g. phtalazinyl), phtalidyl, phtalimidinyl,phtalazonyl, alloxazinyl, dibenzopyronyl (i.e. xanthonyl), xanthionyl,isatyl, isopyrazolyl, isopyrazolonyl, urazolyl, urazinyl, uretinyl,uretidinyl, succinyl, succinimido, benzylsultimyl, benzylsultamyl andthe like, including all possible isomeric forms thereof, wherein eachcarbon atom of said heterocyclic ring may be independently substitutedwith a substituent selected from the group consisting of halogen, nitro,C₁₋₇ alkyl (optionally containing one or more functions or radicalsselected from the group consisting of carbonyl (oxo), alcohol(hydroxyl), ether (alkoxy), acetal, amino, imino, oximino, alkyloximino,amino-acid, cyano, carboxylic acid ester or amide, nitro, thio C₁₋₇alkyl, thio C₃₋₁₀ cycloalkyl, C₁₋₇ alkylamino, cycloalkylamino,alkenylamino, cycloalkenylamino, alkynylamino, arylamino,arylalkylamino, hydroxylalkylamino, mercaptoalkylamino, heterocyclicamino, hydrazino, alkylhydrazino, phenylhydrazino, sulfonyl, sulfonamidoand halogen), C₂₋₇ alkenyl, C₂₋₇ alkynyl, halo C₁₋₇ alkyl, C₃₋₁₀cycloalkyl, aryl, arylalkyl, alkylaryl, alkylacyl, arylacyl, hydroxyl,amino, C₁₋₇ alkylamino, cycloalkylamino, alkenylamino,cyclo-alkenylamino, alkynylamino, arylamino, arylalkylamino,hydroxyalkylamino, mercaptoalkylamino, heterocyclic amino, hydrazino,alkylhydrazino, phenylhydrazino, sulfhydryl, C₁₋₇ alkoxy, C₃₋₁₀cycloalkoxy, aryloxy, arylalkyloxy, oxyheterocyclic,heterocyclic-substituted alkyloxy, thio C₁₋₇ alkyl, thio C₃₋₁₀cycloalkyl, thioaryl, thioheterocyclic, arylalkylthio,heterocyclic-substituted alkylthio, formyl, hydroxylamino, cyano,carboxylic acid or esters or thioesters or amides thereof,thiocarboxylic acid or esters or thioesters or amides thereof; dependingupon the number of unsaturations in the 3 to 10 membered ring,heterocyclic radicals may be sub-divided into heteroaromatic (or“heteroaryl”) radicals and non-aromatic heterocyclic radicals; when aheteroatom of the said non-aromatic heterocyclic radical is nitrogen,the latter may be substituted with a substituent selected from the groupconsisting of C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl, arylalkyl andalkylaryl.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₁₋₇ alkoxy”, “C₃₋₁₀ cycloalkoxy”,“aryloxy”, “arylalkyloxy”, “oxyheterocyclic”, “thio C₁₋₇ alkyl”, “thioC₃₋₁₀ cycloalkyl”, “arylthio”, “arylalkylthio” and “thioheterocyclic”refer to substituents wherein a C₁₋₇ alkyl radical, respectively a C₃₋₁₀cycloalkyl, aryl, arylalkyl or heterocyclic radical (each of them suchas defined herein), are attached to an oxygen atom or a divalent sulfuratom through a single bond, such as but not limited to methoxy, ethoxy,propoxy, butoxy, pentoxy, isopropoxy, sec-butoxy, tert-butoxy,isopentoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, thiomethyl,thioethyl, thiopropyl, thiobutyl, thiopentyl, thiocyclopropyl,thiocyclobutyl, thiocyclopentyl, thiophenyl, phenyloxy, benzyloxy,mercaptobenzyl, cresoxy, and the like.

As used herein with respect to a substituting atom, and unless otherwisestated, the term halogen means any atom selected from the groupconsisting of fluorine, chlorine, bromine and iodine.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “arylalkyl”, “arylalkenyl” and“heterocyclic-substituted alkyl” refer to an aliphatic saturated orunsaturated hydrocarbon monovalent radical (preferably a C₁₋₇ alkyl orC₂₋₇ alkenyl radical such as defined above) onto which an aryl orheterocyclic radical (such as defined above) is already bonded, andwherein the said aliphatic radical and/or the said aryl or heterocyclicradical may be optionally substituted with one or more substituentsselected from the group consisting of halogen, amino, nitro, hydroxyl,sulfhydryl and nitro, such as but not limited to benzyl, 4-chlorobenzyl,phenylethyl, 1-amino-2-phenylethyl, 1-amino-2-[4-hydroxyphenyl]ethyl,1-amino-2-[indol-2-yl]ethyl, styryl, pyridylmethyl, pyridylethyl,2-(2-pyridyl)isopropyl, oxazolylbutyl, 2-thienylmethyl and2-furylmethyl.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention will be described with respect to particularembodiments but the invention is not limited thereto but only by theclaims.

It is to be noticed that the term “comprising”, used in the claims,should not be interpreted as being restricted to the means listedthereafter; it does not exclude other elements or steps. Thus, the scopeof the expression “a device comprising means A and B” should not belimited to devices consisting only of components A and B. It means thatwith respect to the present invention, the only relevant components ofthe device are A and B.

The compounds referred to in the detailed description may be selectedfrom the compounds described in the following list:Compound (I) having the general formula:

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with a substituentchosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and which may compriseup to 4 heteroatoms chosen from the group comprising oxygen, sulphur,and nitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₁ and R₂ may be chosen from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₄-C₂₀-alkyl group, a phenyl group and a benzyl group.The C₁-C₂₀-alkyl group, cyclic C₄-C₂₀-alkyl group, phenyl group andbenzyl group may comprise heteroatoms and substituents.

In a preferred embodiment, R₁ and R₂ are independently selected frommethyl, ethyl or propyl.Compound (II) having the general formula:

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the recited Ar groups may be substituted with asubstituent chosen from the group consisting of a C₁-C₂₀-alkyl,C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and maycomprise up to 4 heteroatoms chosen from the group comprising oxygen,sulphur, and nitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₁ and R₂ may be chosen from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₄-C₂₀-alkyl group, a phenyl group and a benzyl group.The C₁-C₂₀-alkyl group, cyclic C₄-C₂₀-alkyl group, phenyl group andbenzyl group may comprise heteroatoms and substituents. In a preferredembodiment, R₁ and R₂ may independently be selected from methyl, ethylor propyl.

R₃ and R₄ may be chosen from the group comprising a hydrogen atom, aC₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, a phenyl group and abenzyl group, which groups may comprise heteroatoms and substituents. Ina preferred embodiment, R₃ and R₄ may be hydrogen.Compound (III) having the general formula:

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar comprises 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with a substituentchosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic divalent group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₃ and R₄ may be chosen from the group comprising a hydrogen atom and aC₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, a phenyl group and abenzyl group, which groups may comprise heteroatoms and substituents. Ina preferred embodiment, R₃ and R₄ may be hydrogen.Compound (IV) having the general formula:

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with a substituentchosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

X may be selected from the group consisting of Cl, Br or F.

R₅ and R₆ may be selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₄-C₂₀-alkyl group, a phenyl group and a benzyl group,which groups may comprise heteroatoms and substituents.

Compound (V) having the general formulaY—Ar—Y   (V)wherein Y may comprise chloromethyl, bromomethyl or fluoromethyl atomsand wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with a substituentchosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl or a benzyl group and may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.Compound (VI) having the general formula:

wherein Z may be a leaving group. In a preferred embodiment, Z may beselected from the group consisting of Cl, Br, I, —O-Tos, —O-Mes,—O-Triflates, —(NR₁R₁R₁)⁺, —(SR₁R₂)⁺, —OOCR₁ and —SC(S)OR₁. In the aboveformula, Y may be a polarizer group and may be selected form the groupconsisting of —SR₁, —OR₁, —OH, —Cl, —Br, —SO—R₁, —CN, —CO—OR₁ and—S—C(S)OR₁, R₇ and R₈ may independently be —H, R₁, and Ar may be anaromatic or heteroaromatic divalent group. In a preferred embodiment, Armay comprise 4 to 20 carbon atoms. In another embodiment, each of the Argroups may be substituted with a substituent chosen from the groupconsisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, aphenyl or a benzyl group and may comprise up to 4 heteroatoms chosenfrom the group comprising oxygen, sulphur, and nitrogen in the aromaticdivalent group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₁, R₂, R₃ may be equal to R₁, R₂, R₃ as defined for compound (II).

In a first aspect of the present invention, the synthesis of a precursorpolymer (II) starting from the monomer (I) is provided. The presentinvention also provides the synthesis of monomer (I). The second aspectof the invention comprises the conversion reaction of the said precursorpolymer to the relative conjugated polymer.

Furthermore, the present invention comprises the manufacturing of anactive layer from the precursor polymer. The last step of the inventionis the electronic device made from the precursor polymer.

The first aspect thus provides the synthesis of a precursor polymer(II). Therefore, first a monomer has to be provided. Therefore, adithiocarbamic acid sodium salt is added in the solid state to anaromatic or heteroaromatic ring structure of the general formula ofcompound (IV) or to an aromatic or heteroaromatic ring structure withgeneral formula of compound (V) in a mixture of organic solvents. Afterstirring a few hours at room temperature, the reaction product may beextracted with for example ether and dried over magnesium sulphate. Theproduct of that reaction is an arylene or heteroarylene group bearingtwo dithiocarbamate groups in para positions as described in formula(I).

Mono- and bis-dithiocarbamate molecules may in this invention be used asphotoiniferters. An example of such a bifunctional iniferter isp-xylylene bis(N,N-diethyl dithiocarbamate). It was first synthesised in1984 by Otsu et al (T. Otsu, A. Kuriyama, Polym. Bull. 1984, 11, 2,135), and was used for the living radical polymerisation of styrene andmethyl methacrylate. Otsu wrote an extensive review on the iniferterconcept and living radical polymerisation (T. Otsu, J. Polym. Sci., PartA: Polym. Chem. 2000, 38, 12, 2121). The use of p-xylylenebis(N,N-diethyl dithiocarbamate) as a monomer in a polymerisationprocess was not found.

The synthesis of thiophene-2,5-diylbismethylene N,N-diethylthiocarbamate was patented by Nishiyama et al. in 1975 for itsherbicidal activities (Jpn. Tokkyo Koho, No 50004732, 1975), but againno report exists on the use of the dithiocarbamate “thiophene” analogueas a monomer for polymerisation to conjugated semiconductors.

According to the first aspect of the invention the monomer having thegeneral formula (I) is reacted with a basic compound in the presence ofan organic solvent to obtain the precursor polymer (II).

A mixture of different starting monomers of formula (I) may be reactedby using the above method, leading to copolymers. Alternatively, amixture of different starting monomers of formula (I) and of formula(VI) may be polymerised by using this method leading to copolymers.Those copolymers may then be used as polyiniferters in inifertercontrolled free-radical polymerisation to the synthesis of blockcopolymers.

The precursor polymers in accordance with the formula (II), that may beprepared by the invention, preferably may comprise as the Ar group anaromatic or heteroaromatic group chosen from 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl; carbazole-2,7-diyl,of which the nitrogen-containing groups may be substituted on thenitrogen atom with a C₁-C₂₂-alkyl or a C₂-C₁₀-aryl group, while in allgroups the R atoms on the aromatic rings may be substituted by a C₁-C₂₂linear or branched alkyl group, C₄-C₁₄ aryl group, electron-donatinggroups such as C₁-C₂₂ alkoxy and alkylthio groups, and halogen atoms orelectron-attracting groups such as cyano, nitro, and ester groups, whilethe C₁-C₁₄ aryl group itself may be substituted by electron-donating orelectron-attracting groups.

The basic compound may be a metal base, an ammonium base or anon-charged base such as amines like for example triethylamine, pyridineand non-ionic phosphazene bases. The metal in this basic compounds maypreferably be an alkaly metal or an alkaly earth metal, i.e. a metalfrom group I or II. Classes of metal and ammonium bases are metalhydrides, such as NaH or KH, metal hydroxides, such as NaOH, LiOH orKOH, metal alkoxides, such as NaOMe or NaOEt, KOtBu, metal amides, suchas NaNH₂, NaN(SiMe₃)₂, lithiumdiisopropylamide (LDA), organometalcompounds wherein the metal is an alkaly metal or alkaly earth metal,such as for example a C₁₋₂₀ alkyl lithium (e.g. n-BuLi) or a C₁₋₂₀ alkylsodium, Grignard reagents, and ammonium hydroxides. Grignard reagentsare organic magnesium halides preferably dissolved in a nonreactivesolvent (typically dry ethyl ether). The substance is made up of anorganic group, e.g. an alkyl or aryl group, joined by a highly polarcovalent bond to magnesium, while the magnesium is joined by an ionicbond to a halogen ion e.g. bromide or iodide.

The amount of basic compound may vary from 1 to 2 equivalents withrespect to the starting monomer. It may be preferred to use oneequivalent of basic compound because a too high concentration of basiccompound may induce an in situ conversion reaction during thepolymerisation.

In polar aprotic solvents it is preferred to use metal hydrides as theyshow substantially no nucleophilic properties. In polar protic solventsit is preferred to use bases with a pKa larger than the pKa of thesolvent. In this case the solvent is deprotonated and acts as the actualbasic compound. In the method of the present invention, it may bepreferred to use an aprotic solvent. A mixture of solvents may also beused. Examples of solvents which may be used are for example amides ofthe general formula R₅—CONR₆H, amines of the general formula R₇R₇—N—R₈,sulfones of the general formula R₈—SO₂—R₉, sulfoxides of the generalformula R₈—SO—R₉, a solvent from the group consisting of alcohols, suchas for example sec-butanol and all linear or branched C_(n)H_(2n+2)Owhere 1≦n≦20, glycols, polyethers, cyclic ethers, unsaturated ethers,wherein R₅, R₆ are the same or different and denote H, a linear orbranched alkyl group, or R₅ and R₆ together are —(CH₂)₂—, —(CH₂)₃—,CH₂—CH═CH₂—CH₂ or —(CH₂)₄—; and R₇ has the meaning of R₅ or is a phenylgroup which is unsubstituted or substituted by halogen, methyl and/ormethoxy groups; and R₈, R₉ are the same or different and have themeaning of R₇, except H, or R₈ and R₉ together are —(CH₂)₂—, —(CH₂)₃—,—(CH₂)₄— or —CH₂—CH═CH—CH₂—.

The concentration of starting monomer (I) may be determined by thesolubility of the monomer (I). All concentration of the starting monomer(I) in a solvent may be used as long as the monomer (I) is still fullysoluble. However, a concentration of between 0.1 M and 0.3 M maygenerally be preferred.

In a preferred embodiment, a solution of the monomer of formula (I) at agiving temperature may be degassed for a giving time by passing througha continuous nitrogen flow. A basic compound dissolved in an organicsolvent may then be added in one-go to the stirred monomer solution. Thepolymer may then be precipitated in ice-cold water and extracted, washedand dried. The precursor polymer with structural units of formula (II)such obtained is fully soluble in common organic solvents such as forexample THF, cyclohexanone, DMF, chloroform, DMSO, toluene, benzene,dichlorobenzene, dichloromethane, acetone, dioxane and shows an averagemolecular weight (Mw) between 5.000 and 500.000, measured by gelpermeation chromatography relative to polystyrene standards.

In another embodiment, a solution of the monomer of formula (I) and of amonomer of formula (VI) at a giving temperature may be degassed for agiving time by passing through a continuous nitrogen flow. A basiccompound dissolved in an organic solvent may then be added in one-go tothe stirred mixture of monomers solution. The polymer may then beprecipitated in ice-cold water and extracted, washed and dried. Theprecursor polymer containing structural units of formula (II) suchobtained is fully soluble in common organic solvent such as THF,cyclohexanone, DMF, chloroform, DMSO, toluene, benzene, dichlorobenzene,dichloromethane, acetone, dioxane and shows an average molecular weightMw between 5.000 and 1.000.000 and polydispersity between 2 and 15measured by gel permeation chromatography relative to polystyrenestandards.

In a second aspect of this invention, the precursor polymer (II) formedin the first aspect of this invention, is converted into thecorresponding conjugated polymer having the general formula (III).

The precursor polymer may be converted into the corresponding conjugatedpolymer with units of structural formula (III) in two ways: by thermalheating of a precursor polymer solution under inert atmosphere or inthin film prepared by spin-coating or drop-casting under vacuum or underinert atmosphere.

In one embodiment, the polymer (III) may be formed by performing theconversion step in solution. The conversion in solution is only possiblewhen the conjugated polymer is a soluble polymer. The precursor polymer(II) may be subjected to a thermal conversion step at a temperaturebetween 30° C. and 300° C. The conversion reaction of the precursorpolymer (II) starts around 100° C. and is completed at around 250-300°C. depending on the chemical structure of the polymer. In thisembodiment, the precursor polymer (II) may thus be dissolved in asolvent in a giving concentration, typically 0.1 M, and is degassed bypassing through a continuous nitrogen flow for for example 1 hour. Thetemperature may then be increased and the inert atmosphere is maintainedduring the conversion reaction and the cooling down. A typical procedurecomprises heating a ramp from room temperature to the conversiontemperature at 2° C./min, followed by isotherm at the conversiontemperature for 3 hours and cooling down to room temperature. In anotherembodiment, more than one cycle as described above may be applied to thepolymer.

In still another embodiment, the polymer (III) may be formed byperforming the conversion step in thin film. Herefore, glass substratescoated with indium tin oxide (ITO) are cleaned with isopropanol in anultrasonic bath for 20 minutes and dried in nitrogen flow. The activelayer may then be spin-coated on the glass substrate from a solution ofthe precursor polymer (II). A two-step process may be used. A first stepdetermines the film thickness and may be done with a closed cover forfor example 5 seconds at 600 rpm. In a second step the film may be driedwith an open cover for for example 2 minutes at 40 rpm.

The conversion of the precursor polymer (II) in film may be done in aglove box under inert atmosphere on a hot plate from room temperature tothe conversion temperature at 2° C./min followed by 10 minutes at theconversion temperature. The conversion reaction may be carried out alsounder vacuum conditions.

The polymer (III) has to be kept under inert atmosphere.

In a third aspect of the present invention, an electronic devicecomprising a polymer according to formula (III) is disclosed. Theelectronic devices may be, but are not limited hereto, for exampleorganic field effect transistors, bilayer heterojunction organic solarcells and bulk heterojunction organic solar cells. During the processingof the electronic devices, the precursor polymer (II) may be depositedand subsequently subjected to a thermal conversion step (according tothe second aspect of this invention) such that an active layer may beformed.

According to the third aspect of this invention, an organic bulkheterojunction solar cell with acceptable efficiency may be preparedfrom the precursor polymer (II). This is advantageous over prior artmethods, where the conjugated polymer is the starting compound and hencemust be obligatory soluble to be mixed with a soluble C₆₀ derivative(PCBM). As the conversion temperature of the precursor polymer offormula (II) starts relatively at low temperature (e.g. 100-115° C.), itmay be possible to prepare a blend n-type/p-type, used as active layer,by mixing the precursor polymer (II) with PCBM and then carrying out theconversion reaction by heat treatment in thin film keeping the initialchemical structure of PCBM.

For the bulk heterojunction solar cells in accordance to the thirdaspect of this invention the precursor polymer may contain thestructural units of formula (II) wherein R₁, R₂ may be as described informula (II) and wherein Ar may be 2,5-thienylene, which may besubstituted on its 3 and 4 positions by a C₁-C₂₂ linear or branchedalkyl group, C₄-C₁₄ aryl group, electron-donating groups such as C₁-C₂₂linear or branched alkoxy and alkylthio groups, and halogen atoms orelectron-attracting groups such as cyano, nitro, and ester groups, whilethe C₁-C₁₄ aryl group itself may be substituted by electron-donating orelectron-attracting groups, and a soluble C₆₀ derivative may be used asn-type material, such as PCBM. The active layer may be obtained bycarrying out the conversion reaction by heat treatment of the thin filmkeeping intact the initial chemical structure of the soluble C₆₀derivative.

A fourth aspect of this invention comprises the manufacturing of bilayerorganic solar cells, organic transistors and LED's having an activelayer made from a precursor polymer containing structural units offormula (II).

Furthermore, bilayer organic solar cells in accordance with the fourthaspect of this invention are disclosed wherein the precursor polymer maycomprise the structural units of formula (II) wherein R₁, R₂ may be asdescribed in formula (II) and wherein Ar may be 2,5-thienylene, whichmay be substituted on its 3 and/or 4 positions by a C₁-C₂₂ linear orbranched alkyl group, C₄-C₁₄ aryl group, electron-donating groups suchas C₁-C₂₂ linear or branched alkoxy and alkylthio groups, and halogenatoms or electron-attracting groups such as cyano, nitro, and estergroups, while the C₁-C₁₄ aryl group itself may be substituted byelectron-donating or electron-attracting groups. The active layer may beobtained by carrying out the conversion reaction by heat treatment ofthe thin film.

Furthermore, organic transistors in accordance with the fourth aspect ofthis invention are disclosed wherein the precursor polymer may comprisethe structural units of formula (II) wherein R₁, R₂ may be as describedin formula (II) and wherein Ar may be 2,5-thienylene which may besubstituted on its 3 and 4 positions by a C₁-C₂₂ linear or branchedalkyl group, C₄-C₁₄ aryl group, electron-donating groups such as C₁-C₂₂linear or branched alkoxy and alkylthio groups, and halogen atoms orelectron-attracting groups such as cyano, nitro, and ester groups, whilethe C₁-C₁₄ aryl group itself may be substituted by electron-donating orelectron-attracting groups. The active layer may be obtained by carryingout the conversion reaction by heat treatment of the thin film.

Furthermore, Light emitting diodes (LED) in accordance with the fourthaspect of this invention are disclosed wherein the LED may comprise asubstrate having deposited thereon successively a thin film of aprecursor polymer according to structural formula (II), prepared inaccordance to the first aspect of this invention and converted to theconjugated polymer with structural formula (III) by heat treatment inaccordance with the second aspect of this invention and a layer of anelectrical conductor together with means for biasing the thin film andconductor.

EXAMPLE 1

In a first example the synthesis of p-xylylene bis(N,N-diethyldithiocarbamate) with a formula according to formula (I) whereinAr=1,4-phenylene, R₁═R₂═C₂H₅, followed by the polymerisation to theprecursor polymer with a formula according to formula (II) whereinAr=1,4-phenylene, R₁═R₂═C₂H₅, R₃═R₄═H and subsequent conversion to theconjugated polymer with a formula according to formula (III) whereinAr=1,4-phenylene, R₃═R₄═H is illustrated.

To 50 ml of an acetonitrile/water solution (5% vol water) of1,4-bis(tetrahydrothiopheniomethyl)xylene dichloride (6 g, 17.143 mmol),diethyldithiocarbamic acid sodium salt trihydrate (8.87 g, 39.429 mmol)is added as a solid, after which the mixture is stirred at ambienttemperature for two hours. Then, water is added and the desired monomeris extracted with ether (3×100 ml) and dried over MgSO₄. Evaporation ofthe solvent yields 6.2 g, which is 90%, of the pure product as a whitesolid. ¹H NMR (CDCl₃): 7.31 (s, 4H), 4.49 (s, 4H), 4.01 (q, J=7.2 Hz,4H), 3.69 (q, J=7.2 Hz, 4H), 1.25 (2t, J=7.2 Hz, 12H). ¹³C NMR (CDCl₃):195.10, 135.27, 129.57, 49.46, 46.70, 41.79, 12.44, 11.56; MS (EI, m/e):253 (M⁺-SC(S)NEt₂), 148 (SC(S)NEt₂), 105 (M⁺-2×SC(S)NEt₂), 72 (NEt₂)

A solution of the synthesised monomer p-xylenebis(N,N-diethyldithiocarbamate) (500 mg, 1.25 mmol) in dry THF (6.25 ml,0.2 M) at −78° C. (or RT or 0° C.) is degassed for 1 hour by passingthrough a continuous nitrogen flow. An equimolar LDA solution (625 μl ofa 2 M solution in THF) is added in one go to the stirred monomersolution. The THF from the basic solution is neglected in thecalculation of the monomer concentration. The mixture is then kept at−78° C. (or R.T or 0° C.) for 90 minutes while the passing of nitrogenis continued. After this, the solution is allowed to come to 0° C. orethanol (6 ml) is added at −78° C. to stop the reaction (this is notnecessary if the polymerisation is performed at RT or 0° C.). Thepolymer is then precipitated in ice water (100 ml) and extracted withchloroform (3×60 ml). The solvent of the combined organic layers isevaporated under reduced pressure and a second precipitation isperformed in a 1/1 mixture (100 ml) of diethyl ether and hexane at 0° C.The polymer was collected and dried in vacuum. ¹H NMR (CDCl₃): 6.78-7.14(br s, 4H), 5.00-5.30 (br s, 1H), 3.82-4.10 (br s, 2H), 3.51-3.78 (br s,2H), 2.92-3.12 (br s, 2H), 1.04-1.34 (br t, 6H). ¹³C NMR (CDCl₃):194.38, 138.07, 137.17, 129.35, 128.30, 56.92, 49.15, 46.68, 42.63,12.58, 11.65. The residual fractions only contained monomer residues.Polymerisation experiments are carried out at different temperatures.The results are summarised in table 1. In this table, Mw denotes themolecular weight and PD the polydispersity of the conjugated polymer.TABLE 1 Starting monomer with structural units of formula (I) with: Ar =1,4-phenylene, R₁ = Et, R₂ = Et in THF. Conc. Polymerisation Yield Mw(M) temp. (° C.) (%) (g/mol) PD 0.2 −78 90 7300 1.5 −78 to 0 88 150002.1 0 87 31200 4.1 RT 88 36500 5.5

EXAMPLE 2

In a second example, the synthesis of thiophene-2,5-diylbismethyleneN,N-diethyl dithiocarbamate with a formula according to formula (I)wherein Ar=2,5-thienylene and R₁═R₂═C₂H₅, followed by polymerisation tothe precursor polymer with a formula according to formula (II) whereinAr=2,5-thienylene, R₁═R₂═C₂H₅ and R₃═R₄═H, and subsequent conversion tothe conjugated polymer with a formula according to formula (III) whereinAr=2,5-thienylene and R₃═R₄═H, is illustrated.

The preparation of the monomer is analogous to that described in example1, but here a bis-sulphonium salt of formula (IV) whereAr=2,5-thienylene is used. The yield of the reaction is 81%; ¹H NMR(CDCl₃): 6.84 (s, 2H), 4.69 (s, 4H), 4.01 (q, J=7.2 Hz, 4H), 3.69 (q,J=7.2 Hz, 4H), 1.26 (t, J=7.2 Hz, 12H); ¹³C NMR (CDCl₃): 194.29, 138.76,126.77, 49.46, 46.70, 36.72, 12.46, 11.53; MS (EI, m/e): 258(M⁺-SC(S)NEt₂), 148 (SC(S)NEt₂)

The polymerisation of thiophene-2,5-diylbismethylene N,N-diethyldithiocarbamate is analogous to that described in example 1. ¹H NMR(CDCl₃): 6.56-6.72 (br s, 1H), 6.72-6.36 (br s, 1H), 5.22-5.55 (br s,1H), 3.81-4.12 (br q, 2H), 3.48-3.81 (br q, 2H), 3.11-3.40 (br s, 2H),1.01-1.37 (br t, 6H). ¹³C NMR (CDCl₃): 193.61, 140.77, 140.36, 126.15,125.89, 52.50, 49.20, 46.73, 38.37, 12.45, 11.60.

In this example, polymerisation experiments are carried out at differenttemperatures and with different concentrations of starting monomer. Theresults of these experiments are summarised in table 2. TABLE 2 Startingmonomer with structural units of formula (I) with: Ar = 2,5-thienylene,R₁ = Et, R₂ = Et in THF. Conc. Polymerisation Yield Mw (M) temp. (° C.)(%) (g/mol) PD 0.1 −78 47 62800 2.9 −78 to 0 55 90000 5.3 0 42 23800 3.80.2 −78 57 94400 3.1 −78 to 0 56 66100 4.9 0.3 −78 to 0 53 12800 1.4

An organic field effect transistor is then prepared according to thefollowing procedure using the precursor polymer synthesised inaccordance with the method described in this invention. Field-effecttransistors (FETs) may be made of high doped Si substrates. In thisexample, an isolating oxide (SiO₂) of 100 nm is grown thermally on oneside of the Si substrate, while the backside of the substrate is coveredwith an Al layer which acts as a gate electrode. An organic film is thenapplied on top of the oxide. This may be done by means of spin-coating a1% w/v solution of the precursor polymer (II) in chlorobenzene.Measurements of the hole mobility are performed with FETs on whichfurthermore Au source and drain electrodes are evaporated after theorganic film is applied. Before starting the measurement, the precursorpolymer (II) is converted to PTV by heating the sample from roomtemperature to 185° C. at 2° C. per minute. After the sample is hold at185° C. for 10 minutes, it is cooled back to ambient temperature.

A negative gate-voltage induces an accumulation of positive charges in athin conducting channel on the contact surface of the organic film withthe oxide. The field-effect mobilities are determined from thesaturation regime of the drain-source current with the formula:I_(ds,sat)=□_(FE)WC_(ox)(V_(gs)−V_(t))²/2 L wherein W is the width and Lthe length of the conducting channel respectively, C_(ox) is thecapacity of the isolating SiO₂ layer, V_(gs) is the gate voltage andV_(t) is the threshold voltage.

A bilayer organic heterojunction solar cell is prepared according to thefollowing procedure using the precursor polymer synthesised inaccordance with the method described in this invention. TwoITO/PEDOT/PTV/AI devices on glass substrate were tested.

A first test is carried out with a first device wherein pristine is usedan active layer. The second device is made by first converting thespin-coated precursor and afterwards spin-coating [6,6]-PCBM on top ofit, thus forming a bilayer solar cell. J/V curves of the devices in darkand under illumination of 100 mW/cm² light from halogen lamp werestudied. Experimental results of both devices are summarized in table 3.TABLE 3 Starting monomer with structural units of formula (I) with: Ar =2,5-thienylene, R₁ = Et, R₂ =Et. Pristine Bilayer solar cell J_(sc)(mA/cm²) 430 1430 V_(oc) (mV) 435 515 FF (%) 34 48.5 η (%) 0.06 0.36

Organic heterojunction solar cells are prepared according to thefollowing procedure using the precursor polymer synthesised inaccordance with the method described in this invention. Glass substratescoated with ITO (resistance ˜90 ohm per square) are first cleaned withisopropanol in an ultrasonic bath for 20 min and dried in a nitrogenflow. The samples are brought into the glove box with a nitrogenatmosphere. All following steps now are done inside the glove box. An 80nm layer of PEDOT/PSSA is spin-coated on top of the ITO and heat treatedfor 10 min at 180° C. on a hot plate. Then, the sample is cooled down toroom temperature and thereafter the photoactive layer, which is castfrom a 0.5 wt.-% solution of precursor polymer of formula (II) mixedwith a soluble C₆₀ derivative (PCBM) in chlorobenzene, is spincoated ontop of the PEDOT/PSSA. The ratio by weight of the precursor polymer offormula (II) and PCBM is comprised between 1:0.5 and 1:4. The solutionis stirred with a magnetic stirrer for 4 hours at room temperature.

The spincoating of the active layer is a two-step procedure. The firststep, to determine the thickness, is done with a closed cover. Thespinning speed is comprised between 250 rpm and 600 rpm and the spinningtime between 1 and 5 seconds. The second step is to dry the film. Thisstep is performed with an open cover for 3 min at 100 rpm. The convertedfilm may have a thickness between 80 and 100 nm.

The conversion of the precursor polymer is done on a hot plate insidethe glove box from room temperature up to 150° C. with a temperaturestep of 2° C. per minute. Then, the temperature is kept constant at 150°C. for 5 min. After that, the top electrode is evaporated in a vacuum of2.10⁻⁶ mbar. First, a 0.7 nm thick layer of LiF and then a second layerof 150 nm aluminum are evaporated. The active area of each cell is 6mm².

Afterwards, the sample is measured with a solar simulator (AM1.5spectrum). Then, a post-production heat treatment on a hot plate tookplace for several times, starting with 5 min at 70° C. Then the samplesare measured again at room temperature and after that annealing processagain (55 min, in total 1 hour). Five annealing steps are done with atotal time of 9 hours. The results are much higher after 9 hours ofannealing than the initially values. Example of results found for aPolymer/PCBM ratio of 1:1 with V_(oc)=0.41V; J_(sc)=3.42 mA/cm²;FF=34.4%; η=0.48%.

EXAMPLE 3

A third example describes the synthesis ofthiophene-2,5-diylbismethylene N,N-diethyl dithiocarbamate-3,4-diphenylwith a formula according to formula (I) wherein Ar=3,4-diphenyl2,5-thienylene and R₁═R₂═C₂H₅ followed by polymerisation to theprecursor polymer with a formula according to formula (II) whereinAr=3,4-diphenyl 2,5-thienylene and R₃═R₄═H.

For the synthesis of 3,4-Diphenylthiophene, phenylboronic acid (7.12 g,58.394 mmol), 3,4-dibromothiophene (3.05 g, 12.603 mmol) and KF (2.92 g,50.345 mmol) are dissolved in a mixture water and toluene 50/50 (80 mL).Pd(PPh₃)₄ (873 mg) is added as a catalyst. After refluxing the mixturefor 24 hours, an extraction with CHCl₃ (3×50 mL) is performed and thecombined organic phases are dried over MgSO₄. The crude reaction productis purified by column chromatography (silica, n-hexane). The yield is75%; ¹H NMR (CDCl₃): 7.30 (s, 2H), 7.25-7.21 (m, 6H), 7.19-7.16 (m, 4H);MS (EI, m/e): 236 (M⁺)

For the synthesis of 3,4-Diphenyl-2,5-bis chloromethyl thiopheneconcentrated HCl (4.93 g, 50.650 mmol) and acetic anhydride (9.06 g,88.859 mmol) are, under nitrogen atmosphere, added to paraformaldehyde(719 mg, 23.992 mmol) and 3,4-diphenylthiophene (2.1 g, 8.886 mmol) in athree-necked flask. After 4.5 hours refluxing this mixture at 70° C., 10mL of a cold saturated aqueous solution of sodium acetate and 10 mL of a25% aqueous solution of sodium hydroxide are added. The mixture is thenextracted with CHCl₃ (3×50 mL) and dried over MgSO₄. The yield of theprocess is 98%. ¹H NMR (CDCl₃): 7.24-7.21 (m, 6H), 7.08-7.05 (m, 4H),4.67 (s, 4H); MS (EI, m/e): 332 (M⁺), 297 (M⁺-Cl), 261 (M⁺-2 Cl)

For the synthesis of 3,4-diphenylthiophene-2,5-diylbismethyleneN,N-diethyl dithiocarbamate a mixture of3,4-diphenyl-2,5-bischloromethylthiophene (3 g, 8.890 mmol) and sodiumdiethyldithiocarbamate trihydrate (4.6 g, 20.448 mmol) in 10 mL ofmethanol is stirred for three hours at room temperature. The mixture isthen extracted with CHCl₃ (3×50 mL), dried over MgSO₄ and after thesolvent is evaporated, 3.5 g (70% yield) of dithiocarbamate monomer isobtained as a pink solid. ¹H NMR (CDCl₃): 7.24-7.14 (m, 6H), 7.03-7.00(m, 4H), 4.62 (s, 4H), 4.01 (q, J=7.2 Hz, 4H), 3.69 (q, J=7.2 Hz, 4H),1.26 (2t, J=7.2 Hz, 12H). ¹³C NMR (CDCl₃): 194.22, 141.14, 135.33,133.39, 129.99, 127.82, 126.77, 49.31, 46.63, 35.82, 12.39, 11.43.

A solution of the synthesised monomer (400 mg, 0.716 mmol) in dry THF(3.6 ml, 0.2 M) at −78° C. (or room temperature or 0° C.) is degassedfor 15 minutes by passing through a continuous nitrogen flow. Anequimolar LDA solution (360 μL of a 2 M solution in THF/n-hexane) isthen added in one go to the stirred monomer solution. The mixture iskept at −78° C. (or room temperature or 0° C.) for 90 minutes and thepassing of nitrogen is continued. After this, the solution is allowed tocome to 0° C or ethanol (6 ml) is added at −78° C. to stop the reaction(this is not necessary if the polymerisation is performed at R.T or 0°C.). The polymer is precipitated in ice water (100 ml) and extractedwith chloroform (3×60 ml). The solvent of the combined organic layers isevaporated under reduced pressure and a second precipitation isperformed in MeOH. The precursor polymer is collected and dried invacuum. ¹H NMR (CDCl₃): 6.78-7.14 (br s, 4H), 5.00-5.30 (br s, 1H),3.82-4.10 (br s, 2H), 3.51-3.78 (br s, 2H), 2.92-3.12 (br s, 2H),1.04-1.34 (br t, 6H). ¹³C NMR (CDCl₃): 194.38, 138.07, 137.17, 129.35,128.30, 56.92, 49.15, 46.68, 42.63, 12.58, 11.65. TABLE 4 Startingmonomer with structural units of formula (I) wherein Ar =3,4-diphenyl-2,5-thienylene, R₁ = Et, R₂ = Et in THF. Conc.Polymerisation Yield Mw (g/mol) (M) temp. (° C.) (%) in DMF PD 0.2 0 3050400 1.4 −78 60 29800 1.2 −78 to 0 50 24600 1.2

EXAMPLE 4

In a fourth example, a copolymerisation reaction between p-xylenebis(N,N-diethyldithiocarbamate) (Formula (I) wherein Ar is a thiophenering and R₁═R₂═C₂H₅ and further denoted as A) and2,5-bis[ethoxy(thiocarbonyl)thiomethyl]thiophene (Formula (VI) whereinAr is a thiophene ring, R₇═R₈═H and Y=Z=SC(S)OEtEt, and further denotedas B) is illustrated.

A solution of monomer p-xylene bis(N,N-diethyldithiocarbamate) (375,250, 125 mg respectively) and monomer2,5-bis[ethoxy(thiocarbonyl)thiomethyl]thiophene (108, 217, 325 mgrespectively) in dry THF (6.16 ml, 0.2 M) at −78° C. is degassed for 1hour by passing through a continuous nitrogen flow. An equimolar LDAsolution (616 μl of a 2 M solution in THF) is added in one go to thestirred monomer solution. The mixture is kept at −78° C. for 90 minutesand the passing of nitrogen is continued. After this, ethanol (6 ml) isadded at −78° C. to stop the reaction. The polymer is precipitated inice water (100 ml) and extracted with chloroform (3×60 ml). The solventof the combined organic layers is evaporated under reduced pressure anda second precipitation is performed in a 1/1 mixture (100 ml) of diethylether and hexane at 0° C. The polymer is collected and dried in vacuum.

Experiments are carried out at different ratios of A and B. The resultsare summarised in table 5. TABLE 5 Starting monomer as a mixture ofmonomer with structural units of formula (I) wherein Ar =2,5-thienylene, R₁ = Et, R₂ = Et, (A), and of monomer with structuralunits of formula (VI) wherein Ar = 2,5-thienylene, R₇ = R₈ = H and Y = Z= SC(S)OEtEt, (B) Yield Mw Molar Ratio A/B (%) (g/mol) PD 100/0  5794400 3.1 75/25 56 372600 13.3 50/50 69 309900 12.8 25/75 70 202700 10.3 0/100 50 137200 7.8

It is to be understood that although preferred embodiments, specificconstructions and configurations, as well as materials, have beendiscussed herein for devices according to the present invention, variouschanges or modifications in form and detail may be made withoutdeparting from the scope and spirit of this invention.

1. A method for the preparation of a precursor polymer having thegeneral formula:

wherein Ar is an aromatic divalent group or a heteroaromatic divalentgroup, wherein R₁ and R₂ are independently from each other selected fromthe group consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkylgroup, aryl groups, alkylaryl groups, arylalkyl groups and heterocyclicgroups and wherein R₃ and R₄ are independently from each other hydrogenor an organic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, aryl groups, alkylaryl groups,arylalkyl groups and heterocyclic groups, said method comprising thesteps of providing a monomer having the general formula:

wherein Ar is an aromatic divalent group or an heteroaromatic divalentgroup, wherein R₁ and R₂ are independently from each other selected fromthe group consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkylgroup, aryl groups, alkylaryl groups, arylalkyl groups and heterocyclicgroups, and reacting said monomer with a basic compound, comprising R₃and R₄, in the presence of an organic solvent to obtain said precursorpolymer.
 2. A method according to claim 1 wherein said basic compound isselected from the group consisting of a metal hydride, a metal alkoxide,a metal hydroxide, a metal amide, a metal amine, an organometal compoundwherein the metal is an alkaly metal or alkaly earth metal, a grignardreagent and ammonium hydroxide and pyridine or phosphazene bases.
 3. Amethod according to claim 1 or 2, wherein the amount of basic compoundis between 1 and 2 equivalents with respect to the monomer.
 4. A methodaccording to any of the previous claims, wherein the concentration ofmonomer (I) is between 0.1 M and 0.3 M.
 5. A method according to any ofthe previous claims, wherein the Ar is an aromatic divalent group with 4to 20 carbon atoms which may be substituted with one or moresubstituents independently selected from the group consistingC₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, a phenyl group or abenzyl group and which may comprise up to 4 heteroatoms chosen from thegroup comprising oxygen, sulphur, and nitrogen in the aromatic divalentgroup.
 6. A method according to any of the previous claims, wherein saidaromatic or heteroaromatic divalent group is selected from the groupconsisting of 1,4-phenylene; 2,6-naphthalenediyl; 1,4-naphthalenediyl;1,4-anthracenediyl; 2,6-anthracenediyl; 9,10-anthracenediyl;2,5-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl.
 7. A method accordingto claim 5, wherein said aromatic or heteroaromatic divalent group is1,4-phenylene or 2,5-thienylene.
 8. A method according to any of theprevious claims, wherein said aromatic or heteroaromatic divalent groupis 2,5 thienylene.
 9. A method according to any of the previous claims,wherein R₁ and R₂ are independently from each other selected from thegroup consisting of methyl, ethyl and isopropyl.
 10. A method accordingto any of the previous claims, wherein said organic solvent is anaprotic solvent.
 11. A method according to any of the previous claims,wherein said reacting step is performed at a temperature between −78° C.and 200° C.
 12. A method according to any of the previous claims,wherein said reacting step is performed at a temperature between −20° C.and 30° C.
 13. A method for the preparation of a polymer comprising thestructural units

wherein Ar is an aromatic divalent group or an heteroaromatic divalentgroup, wherein R₃ and R₄ are independently from each other hydrogen oran organic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, aryl groups, alkylaryl groups,arylalkyl groups and heterocyclic groups, said method comprising thesteps of: providing at least one precursor polymer having the generalformula:

wherein Ar is an aromatic group or an heteroaromatic group, wherein R₁and R₂, are independently from each other an organic group selected fromthe group consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkylgroup, aryl groups, alkylaryl groups, arylalkyl groups and heterocyclicgroups, and wherein R₃ and R₄ are independent from each other hydrogenor an organic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, aryl groups, alkylaryl groups,arylalkyl groups and heterocyclic groups, and subjecting said precursorpolymer to a thermal conversion step at a temperature between 30° C. and300° C.
 14. A method according to claim 13, wherein the Ar is anaromatic divalent group with 4 to 20 carbon atoms which may besubstituted with one or more substituents independently selected fromthe group consisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl group or a benzyl group and which maycomprise up to 4 heteroatoms chosen from the group comprising oxygen,sulphur, and nitrogen in the aromatic divalent group.
 15. A methodaccording to claim 13 or 14, wherein said aromatic or heteroaromaticdivalent group is selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl.
 16. A methodaccording to any of claims 13 to 15, wherein said aromatic orheteroaromatic divalent group is 1,4-phenylene or 2,5-thienylene.
 17. Amethod according to any of the claims 13 to 16, wherein said aromatic orheteroaromatic divalent group is 2,5 thienylene.
 18. A method accordingto any of claims 13 to 17, wherein R₁ and R₂ are independently selectedfrom the group consisting of methyl, ethyl and propyl.
 19. A methodaccording to any of claims 13 to 18, wherein R₃ and R₄ are hydrogen. 20.A method according to any of claims 13 to 19, wherein the polymer is aconjugated arylene vinylene polymer.
 21. A method according to claim 20,wherein said conjugated arylene vinylene polymer is poly (2,5 thienylenevinylene).
 22. A method according to any of claims 13 to 21, whereinsaid precursor polymer is in the form of a thin film precursor polymerlayer and wherein said thermal conversion step is performed under inertatmosphere.
 23. A method according to any of claims 13 to 22, whereinsaid precursor polymer is dissolved in a solvent followed by a degassingstep.
 24. A precursor polymer compound having the general formula

wherein Ar is an aromatic group or an heteroaromatic divalent group,wherein R₁, R₂, R₃ and R₄ are independently from each other hydrogen oran organic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, aryl groups, alkylaryl groups,arylalkyl groups and heterocyclic groups.
 25. A precursor polymercompound according to claim 24, wherein the Ar is an aromatic divalentgroup with 4 to 20 carbon atoms which may be substituted with one ormore substituents independently selected from the group consisting ofC₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, a phenyl group or abenzyl group and which may comprise up to 4 heteroatoms chosen from thegroup comprising oxygen, sulphur, and nitrogen in the aromatic divalentgroup.
 26. A precursor polymer according to claim 24 or 25, wherein saidaromatic or heteroaromatic divalent group is selected from the groupconsisting of 1,4-phenylene; 2,6-naphthalenediyl; 1,4-naphthalenediyl;1,4-anthracenediyl; 2,6-anthracenediyl; 9,10-anthracenediyl;2,5-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl.
 27. A precursorpolymer according to any of claims 24 to 26, wherein said aromatic orheteroaromatic divalent group is 1,4-phenylene or 2,5-thienylene.
 28. Aprecursor polymer according to any of claims 24 to 27, wherein saidaromatic or heteroaromatic divalent group is 2,5 thienylene.
 29. Aprecursor polymer according to any of claims 24 to 28, wherein R₁ and R₂are independently selected from the group consisting of methyl, ethyland propyl.
 30. A precursor polymer according to any of claims 24 to 29,wherein R₃ and R₄ are hydrogen.
 31. A precursor polymer according to anyof claims 24 to 30, wherein said precursor polymer has an averagemolecular weight between 5000 and 500000 Daltons.
 32. A precursorpolymer according to any of claims 24 to 31, wherein said precursorpolymer has a polydispersity between 1.5 and 5.5.
 33. A precursorpolymer according to any of claims 24 to 32, wherein said precursorpolymer has a polydispersity below
 2. 34. A conjugated arylene orheteroarylene vinylene polymer having the general formula:

wherein Ar is an aromatic group or an heteroaromatic divalent group,wherein R₃ and R₄ are independently from each other hydrogen or anorganic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, aryl groups, alkylaryl groups,arylalkyl groups and heterocyclic groups, and wherein n is an integerfrom 5 to 2000, characterized in that the polymer shows a peak at awavelength higher than 520 nm in the absorption spectrum.
 35. Aconjugated arylene or heteroarylene vinylene polymer according to claim34, wherein Ar is an aromatic divalent group with 4 to 20 carbon atomswhich may be substituted with one or more substituents independentlyselected from the group consisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl group or a benzyl group and which maycomprise up to 4 heteroatoms chosen from the group comprising oxygen,sulphur, and nitrogen in the aromatic divalent group.
 36. A conjugatedarylene or heteroarylene vinylene polymer according to claim 34 or 35,wherein said aromatic or heteroaromatic divalent group is selected fromthe group consisting of 1,4-phenylene; 2,6-naphthalenediyl;1,4-naphthalenediyl; 1,4-anthracenediyl; 2,6-anthracenediyl;9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-dyil; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl.
 37. A conjugatedarylene or heteroarylene vinylene polymer according any of claims 34 to36, wherein said aromatic or heteroaromatic divalent group is1,4-phenylene or 2,5-thienylene.
 38. A conjugated arylene orheteroarylene vinylene polymer according to any of claims 34 to 37,wherein said aromatic or heteroaromatic divalent group is 2,5thienylene.
 39. A conjugated arylene or heteroarylene vinylene polymeraccording to any of claims 34 to 38, wherein R₃ and R₄ are hydrogen. 40.A conjugated arylene or heteroarylene vinylene polymer according to anyof claims 34 to 39, wherein said polymer is poly (2,5 thienylenevinylene).
 41. A conjugated arylene or heteroarylene vinylene polymeraccording to any of claims 34 to 40, wherein the average molecularweight is between 5000 daltons and 500000 daltons.
 42. A conjugatedarylene or heteroarylene vinylene polymer according to any of claims 34to 41, wherein the polydispersity of the polymer is between 1.5 and 5.5.43. A conjugated arylene or heteroarylene vinylene polymer according toany of claims 34 to 42, wherein said polymer is a linear polymer.
 44. Adevice comprising a layer according to any of claims 34 to
 43. 45. Adevice according to claim 44, wherein said device is a solar cell, alight-emitting diode or an integrated circuit.